Can I use nginx as reverse proxy in this particular case?

Question

I need to know if it is possible to use Nginx as a reverse proxy to serve several web apps hosted each one in a different Raspberry Pi.

As it can be seen in the diagram, the Raspberries will be all connected to an unmanaged switch, the first switch I intend to install nginx so it could serve as reverse proxy depending on the website requested from the internet. Ex: wwww.site1.com, www.site2.www, etc

Is this possible? Will I be able to access those RPis from a computer connected to the modem, not to the switch?

Note: The modem is a wifi modem and the switch is an unmanaged wired switch.

Apologies for my poor drawing skills, and thanks for any help. I need to know if this idea is possible before buying all this stuff.

Answer 1

This is the nginx conf on the side of the head node:

server {
  listen 80;
  server_name www.codingindfw.com codingindfw.com;
  location / { rewrite ^ https://$host$request_uri permanent;}
}

server{
  listen 443 ssl;
  server_name www.codingindfw.www codingindfw.com;

  client_max_body_size 4G;

  ssl_certificate /etc/letsencrypt/live/www.koohack.com/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/www.koohack.com/privkey.pem;

  ssl_protocols       TLSv1 TLSv1.1 TLSv1.2;
  ssl_ciphers         HIGH:!aNULL:!MD5;

  access_log /var/log/nginx/access.log;
  error_log /var/log/nginx/error.log;

  location / {
    proxy_pass              http://192.168.0.8;
    proxy_set_header        Host $host;
    proxy_set_header        X-Real-IP $remote_addr;
    proxy_set_header        X-Forwarded-for $remote_addr;
    port_in_redirect        off;
    proxy_redirect          http://192.168.0.8/ /;
    }
}

And this is the nginx conf file on the client running the actual Django app:

server {
    listen 80 default_server;
    server_name www.codingindfw.com;

    client_max_body_size 4G;

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    location = /favicon.ico { access_log off; log_not_found off; }

    location /static/ {
        root /home/pi/coding-in-dfw;
    }

    location /media/ {
        root  /home/pi/coding-in-dfw;
    }

    location / {
            include proxy_params;
            proxy_pass http://unix:/home/pi/coding-in-dfw/mysocket.sock;
    }
}

Answer 2

I think, it is possible, but there are some requrements:

• static external IP assigned to Modem;

• static IP's on RPi's;

• correct forwarding rules on modem.

I mean, you need forward all requests like the following:

modem:80 -> rp0:80

modem:443 -> rp0:443

On rp0 ports may differ from 80 and 443, so, please, set up correct rules and note it in nginx config.

After that set up upstreams or use IP's of rp1-3 in websites configs:

upstream rp1 {
    server 192.168.1.11:port;
}
upstream rp2 {
    server 192.168.1.12:port;
}
upstream rp3 {
    server 192.168.1.13:port;
}

Replace port with port, which is listened on apropriate RPi. Website configs will be like the following:

server {
server_name site1.com www.site1.com ;
location / { proxy_pass http://rp1 ; }
}
server {
server_name site2.com www.site2.com ;
location / { proxy_pass http://rp2 ; }
}

Add any params you need. Also, if you are going to host some static websites, the best way is too place them on rp0.

EDIT 1 Example of working config:

server {
listen 80;
server_name site1.com www.site1.com ;
location / { rewrite ^ https://$host$request_uri permanent;}
}

server {
listen              443 ssl;
server_name         site1.com www.site1.com;

ssl_certificate     /etc/letsencrypt/live/site1/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/site1/key.pem;
ssl_protocols       TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers         HIGH:!aNULL:!MD5;
location / {
    proxy_pass              http://rp1;
    proxy_set_header        Host $host;
    proxy_set_header        X-Real-IP $remote_addr;
    proxy_set_header        X-Forwarded-for $remote_addr;
    port_in_redirect        off;
    proxy_redirect          http://rp1/ /;
}

Please, note, if you are going to use Letsencrypt, the best way is to set up certbot (or smth else) on rp0. It will be easier to renew certs automatically. Also, use /etc/letsencrypt/live/site1/fullchain.pem . In order to use multiple SSL-domains, be sure that install nginx supports SNI:

# nginx -V
nginx version: nginx/1.14.0
built by gcc 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC)
built with OpenSSL 1.0.2k-fips  26 Jan 2017
TLS SNI support enabled